Encapsulating composition

ABSTRACT

The present application relates to an encapsulating composition and an organic electronic device comprising the same, and provides an encapsulating composition which can effectively block moisture or oxygen introduced into an organic electronic device from the outside to secure the lifetime of the organic electronic device, is possible to realize a top emission type organic electronic device, is applicable to an inkjet method and can maintain reliability of a sealing structure under severe conditions such as high temperature and high humidity while providing a thin display, and an organic electronic device comprising the same.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority based on Korean Patent Application No. 10-2016-0167797 filed on Dec. 9, 2016, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present application relates to an encapsulating composition, an organic electronic device comprising the same, and a method for manufacturing the organic electronic device.

BACKGROUND ART

An organic electronic device (OED) means a device comprising a layer of an organic material that generates an alternating current of electric charges using holes and electrons, and an example thereof may include a photovoltaic device, a rectifier, a transmitter and an organic light emitting diode (OLED), and the like.

The organic light emitting diode (OLED) among the organic electronic devices has lower power consumption and faster response speed, than conventional light sources, and is advantageous for thinning display devices or illuminations. In addition, the OLED has excellent space utilization, so that it is expected to be applied in various fields covering various portable devices, monitors, notebooks, and televisions.

In commercialization and application expansion of OLEDs, the most important problem is a durability problem. Organic materials and metal electrodes, and the like, contained in OLEDs are very easily oxidized by external factors such as moisture. Thus, products comprising OLEDs are highly sensitive to environmental factors. Accordingly, various methods have been proposed to effectively block penetration of oxygen or moisture from the outside into organic electronic devices such as OLEDs.

DISCLOSURE Technical Problem

The present application provides an encapsulating composition which can effectively block moisture or oxygen introduced into an organic electronic device from the outside to secure the lifetime of the organic electronic device, is possible to realize a top emission type organic electronic device, is applicable to an inkjet method and can maintain reliability of a sealing structure under severe conditions such as high temperature and high humidity while providing a thin display, and an organic electronic device comprising the same.

Technical Solution

The present application relates to an encapsulating composition. The encapsulating composition may be a sealing material applied to sealing or encapsulating an organic electronic device such as, for example, an OLED. In one example, the encapsulating composition of the present application can be applied to sealing or encapsulating the entire surface of an organic electronic element. Thus, after the encapsulating composition is applied to the encapsulation, it may be present in an organic layer form sealing the entire surface of the organic electronic element. In this specification, the organic layer, the sealing layer, the sealing material and the sealing structure may be used in the same sense. In addition, the organic layer may be laminated on the organic electronic element together with a protective layer and/or an inorganic layer, which is described below, to form a sealing structure.

In an embodiment of the present application, the present application relates to an encapsulating composition for sealing an organic electronic element applicable to an inkjet process, where the composition may be designed to have appropriate physical properties, when it has been discharged onto a substrate by using inkjet printing capable of non-contact type patterning.

In this specification, the term “organic electronic device” means an article or device having a structure comprising an organic material layer that generates an alternating current of electric charges using holes and electrons between a pair of electrodes facing each other, and an example thereof may include a photovoltaic device, a rectifier, a transmitter and an organic light emitting diode (OLED), and the like, but is not limited thereto. In one example of the present application, the organic electronic device may be an OLED.

An exemplary encapsulating composition may be provided in the form of a sealing layer after curing. The encapsulating composition cured in the form of the sealing layer may have a surface energy in a range of 20 mN/m to 30 mN/m and a surface roughness of 3.5 nm or less. More specifically, the encapsulating composition in the form of the sealing layer may have a surface energy of 21 mN/m to 29 mN/m, 22 mN/m to 28 mN/m, 23 mN/m to 27 mN/m, 24 mN/m to 26 mN/m or 24.2 mN/m to 25.8 mN/m. Furthermore, the encapsulating composition in the form of the sealing layer may have a surface roughness of 3.5 nm or less, 3.3 nm or less, 2.8 nm or less, 2.1 nm or less, 1.8 nm or less, 1.3 nm or less, 0.8 nm or less, or 0.35 nm or less, where the lower limit is not particularly limited, but may be 0 or 0.01 nm. By controlling the surface physical properties of the sealing layer to the above range, the present application can realize an excellent adhesion when the encapsulating composition seals the organic electronic element. As described below, in the organic electronic element, a protective layer is formed on the electrode, and the encapsulating composition is provided in the form of an organic sealing layer on the protective layer. Furthermore, an inorganic layer is further deposited on the encapsulating composition. In forming a sealing structure of an organic electronic element by positioning a sealing layer between the protective layer and the inorganic layer through an encapsulating composition, the present application can maintain adhesion between layers even under severe conditions of high temperature and high humidity, and provide reliability of the organic electronic device.

In an embodiment of the present application, the surface energy (γ^(surface), mN/m) can be calculated as γ^(surface)=γ^(dispersion)+γ^(polar). The surface energy may be a value measured by a known measuring method. In one example, the surface energy can be measured using a drop shape analyzer (DSA100 product from KRUSS). For example, after an encapsulating composition for measuring the surface energy is applied on a glass substrate or a SiNx substrate to any one thickness of about 50 μm or 1 to 50 μm to form a sealing layer (spincoater), it is dried at room temperature for about 1 minute to 30 minutes under a nitrogen atmosphere and then UV-cured with any one intensity of 500 to 3000 mW/cm² through any one light quantity of 1000 to 5000 mJ/cm². The process of dropping the deionized water whose surface tension is known on the layer after curing, and obtaining the contact angle thereof is repeated five times to obtain an average value of the obtained five contact angle values, and identically, the process of dropping the diiodomethane whose surface tension is known thereon and obtaining the contact angle thereof is repeated five times to obtain an average value of the obtained five contact angle values. Then, the surface energy can be obtained by substituting the value (Strom value) regarding the solvent surface tension by the Owens-Wendt-Rabel-Kaelble method using the obtained average values of the contact angles for the deionized water and diiodomethane.

Also, in an embodiment of the present application, the surface roughness is measured by applying the encapsulating composition to a glass substrate or a SiNx substrate to any one thickness of about 50 μm or 1 to 50 μm, and UV-curing it with any one intensity of 500 to 3000 mW/cm² through any one light quantity of 1000 to 5000 mJ/cm² to form a sealing layer. The surface roughness can be measured using NX10 from Park Systems.

In an embodiment of the present application, the encapsulating composition may comprise a curable compound having at least one or more curable functional groups. The curable functional group may be, for example, one or more selected from an oxetane group, a glycidyl group, an isocyanate group, a hydroxyl group, a carboxyl group, an amide group, an epoxide group, a sulfide group, an acetal group and a lactone group.

In one example, the curable compound may comprise a curable compound having a cyclic structure in its molecular structure and having at least two or more curable functional groups. The compound having a cyclic structure in its molecular structure may have ring constituent atoms in the molecular structure in a range of 3 to 10, 4 to 8, or 5 to 7, and one or two or more, or 10 or less of the cyclic structures may be present in the compound.

In addition, the curable compound may comprise a monofunctional curable compound. The monofunctional curable compound may have one curable functional group. The monofunctional curable compound may be comprised in the composition in a range of 65 to 165 parts by weight, 68 to 162 parts by weight, 73 to 160 parts by weight, 78 to 159 parts by weight, 85 to 158 parts by weight or 90 to 157 parts by weight, relative to 100 parts by weight of the curable compound having a cyclic structure. In this specification, the term “part by weight” herein may mean a weight ratio between the respective components. By controlling the content ratio of the monofunctional curable compound and the curable compound having a cyclic structure, the present application prevents occurrence of haze due to no reaction or over curing to realize optical characteristics, prevents damage to the organic electronic element and maintains excellent adhesion to an adherend after curing, while making it possible to provide a composition capable of an inkjet process. In one example, the curable compound may further comprise a linear or branched aliphatic curable compound. The aliphatic curable compound may have at least two or more curable functional groups. Also, the linear or branched aliphatic compound may be comprised in the encapsulating composition in a range of 20 parts by weight or more, less than 205 parts by weight, 23 parts by weight to 204 parts by weight, 30 parts by weight to 203 parts by weight, 34 parts by weight to 202 parts by weight, 40 parts by weight to 201 parts by weight, 60 parts by weight to 200 parts by weight or 100 parts by weight to 173 parts by weight, relative to 100 parts by weight of the compound having a cyclic structure. By controlling the content ratio of the curable compound having a cyclic structure and the aliphatic curable compound, the present application can prevent haze occurrence due to no reaction or over curing to realize optical characteristics, prevent damage of an organic electronic element due to the nature of an organic layer composition that is directly applied on the element and control the physical properties so that it can be applied on the element by the inkjet method.

In one example, the curable compound may be an epoxy compound, and when the compound is an epoxy compound, the curable compound having a cyclic structure may have an epoxy equivalent in a range of 50 to 350 g/eq, 73 to 332 g/eq, 94 to 318 g/eq or 123 to 298 g/eq. Also, the linear or branched aliphatic compound may have an epoxy equivalent in a range of 120 e/eq to 375 e/eq or 120 e/eq to 250 e/eq. By controlling the epoxy equivalent of the curable compound to be low, the present application can prevent the viscosity of the composition from becoming excessively high to render the inkjet process impossible, while improving the curing completion degree after curing of the sealing material, and simultaneously provide moisture barrier properties and excellent curing sensitivity. In this specification, the epoxy equivalent is grams (g/eq) of a resin containing one gram equivalent of epoxy group, which can be measured according to the method defined in JIS K 7236.

In addition, the curable compound may further comprise a curable compound having an oxetane group. The curable compound having an oxetane group may have at least two or more oxetane groups. The curable compound having an oxetane group may be comprised in an amount of 50 to 150 parts by weight, 55 to 145 parts by weight, 60 to 140 parts by weight, 65 to 140 parts by weight, 70 to 135 parts by weight, 75 to 130 parts by weight, 80 to 125 parts by weight, 85 to 120 parts by weight or 88 to 115 parts by weight, relative to 100 parts by weight of the curable compound having a cyclic structure and the monofunctional curable compound. By controlling the content ratio between the curable compounds, the present application can form an organic layer on an organic electronic element by an inkjet method, and the applied encapsulating composition can provide an organic layer which has excellent spreadability in a short time and has excellent curing strength after being cured.

The compound having an oxetane group may have a weight average molecular weight in a range of 150 to 1,000 g/mol, 173 to 980 g/mol, 188 to 860 g/mol, 210 to 823 g/mol or 330 to 780 g/mol. By controlling the weight average molecular weight of the compound having an oxetane group to be low, the present application can realize excellent printability when applied to inkjet printing and simultaneously provide moisture barrier property and excellent curing sensitivity. In this specification, the weight average molecular weight means a value converted to standard polystyrene measured by GPC (gel permeation chromatograph). In one example, a column made of a metal tube having a length of 250 to 300 mm and an inner diameter of 4.5 to 7.5 mm is filled with 3 to 20 mm polystyrene beads. When a solution diluted by dissolving a substance to be measured in a THF solvent is passed through the column, the weight average molecular weight can be indirectly measured according to a flowing time. It can be detected by plotting amounts separated from the column by size for each time.

The compound having an oxetane group may have a boiling point in a range of 90 to 300° C., 98 to 270° C., 110 to 258° C., or 138 to 237° C. By controlling the boiling point of the compound to the above range, the present application can provide a sealing material which can have excellent moisture barrier properties from the outside while realizing excellent printability even at a high temperature in an inkjet process, and prevent damage applied to the element due to suppressed outgas. In this specification, the boiling point may be measured at 1 atm, unless otherwise specified.

In one example, the encapsulating composition of the present application may have a contact angle to glass of 30° or less, 25° or less, 20° or less, or 12° or less. The lower limit is not particularly limited, but may be 1° or 3° or more. By adjusting the contact angle to 300 or less, the present application can ensure spreadability in a short time in the inkjet coating, thereby forming an organic layer of a thin film. In the present application, the contact angle may be measured by applying a drop of the encapsulating composition onto glass using a sessile drop measurement method, which may be an average value measured after applying 5 times.

In one example, the compound having a cyclic structure in its molecular structure may be exemplified by 3,4-epoxycyclohexylmethyl 3′,4′-epoxycyclohexanecarboxylate (EEC) and derivatives, dicyclopentadiene dioxide and derivatives, vinylcyclohexene dioxide and derivatives, or 1,4-cyclohexanedimethanol bis(3,4-epoxycyclohexanecarboxylate) and derivatives, but is not limited thereto.

In this specification, the curable compound having a cyclic structure may be an aliphatic compound, which may be distinguished from the linear or branched aliphatic compound in that it has a cyclic structure. Also, the curable compound having an oxetane group may be a linear, branched or cyclic aliphatic compound, but it may be distinguished from the two compounds mentioned above in that it has an oxetane group. Furthermore, the monofunctional curable compound is a compound having one curable functional group, which may be distinguished from the above three compounds.

In one example, the structure of the curable compound comprising the oxetane group is not limited as long as it has the functional group, and for example, OXT-221, CHOX, OX-SC, OXT101, OXT121, or OXT212 from TOAGOSEI, or EHO, OXBP, OXTP or OXMA from ETERNACOLL may be exemplified. Also, the linear or branched aliphatic curable compound may include aliphatic glycidyl ether, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, propylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether or neopentyl glycol diglycidyl ether, but is not limited thereto. Furthermore, the monofunctional curable compound may comprise a glycidyl ether compound as an aliphatic alcohol, or glycidyl ester as an alkyl carboxylic acid.

In an embodiment of the present application, the encapsulating composition may further comprise a surfactant. In one example, the surfactant may comprise a polar functional group, and the polar functional group may be present at the compound structural end of the surfactant. The polar functional group may include, for example, a carboxyl group, a hydroxyl group, a phosphate, an ammonium salt, a carboxylate group, a sulfate or a sulfonate. Furthermore, in an embodiment of the present application, the surfactant may be a non-silicone-based surfactant or a fluorine-based surfactant. The non-silicone-based surfactant or the fluorine-based surfactant may be applied together with the above-mentioned compound having a curable compound to provide excellent coating properties on the organic electronic element. On the other hand, in the case of a surfactant comprising a polar reactive group, it may have high affinity with the other components of the above-described encapsulating composition, thereby realizing an excellent effect in terms of adhesion. In an embodiment of the present application, a hydrophilic fluorine-based surfactant or non-silicone-based surfactant may be used to improve inkjet coating properties of a base material.

Specifically, the surfactant may be a polymer type or oligomer type fluorine-based surfactant. As the surfactant, a commercially available product may be used, which may be selected from the group consisting of Glide 100, Glide 110, Glide 130, Glide 460, Glide 440, Glide 450 or RAD 2500 from TEGO, Megaface F-251, F-281, F-552, F554, F-560, F-561, F-562, F-563, F-565, F-568, F-570 and F-571 from DIC (DaiNippon Ink Chemicals), or Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141 and S-145 from Asahi Glass Co., Fluorad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430 and FC-4430 from Sumitomo 3M Ltd., or Zonyl FS-300, FSN, FSN-100 and FSO from DuPont and BYK-350, BYK-354, BYK-355, BYK-356, BYK-358N, BYK-359, BYK-361N, BYK-381, BYK-388, BYK-392, BYK-394, BYK-399, BYK-3440, BYK-3441, BYKETOL-AQ, BYK-DYNWET 800 from BYK, and the like.

The surfactant may be included in an amount of 0.01 to 10 parts by weight, 0.05 to 10 parts by weight, 0.1 to 10 parts by weight, 0.5 to 8 parts by weight, or 1 to 4 parts by weight, relative to 100 parts by weight of the entire curable compound. Within the content range, the present application makes it possible that the encapsulating composition is applied to an inkjet method to form an organic layer of a thin film.

In an embodiment of the present application, the encapsulating composition may further comprise a photoinitiator. The photoinitiator may be an ionic photoinitiator. Also, the photoinitiator may be a compound absorbing a wavelength in a range of 200 nm to 400 nm. By using the photoinitiator, the present application can realize excellent curing properties in a specific composition of the present application.

In one example, the photoinitiator may be a cationic photopolymerization initiator. As the cationic photopolymerization initiator, a known material in the art can be used and for example, it may include a compound having a cation moiety comprising aromatic sulfonium, aromatic iodonium, aromatic diazonium or aromatic ammonium and an anion moiety comprising AsF₆ ⁻, SbF₆ ⁻, PF₆ ⁻, or tetrakis(pentafluorophenyl) borate. Furthermore, as the cationic photopolymerization initiator, an ionized cationic initiator of onium salt or organometallic salt series or a non-ionized cationic photopolymerization initiator of organic silane or latent sulfonic acid series can be exemplified. Diaryliodonium salt, triarylsulfonium salt or aryldiazonium salt and the like can be exemplified as the initiator of the onium salt series, iron arene or the like can be exemplified as the initiator of the organometallic salt series, o-nitrobenzyl triaryl silyl ether, triaryl silyl peroxide or an acyl silane and the like can be exemplified as the initiator of the organosilane series, and α-sulfonyloxy ketone or α-hydroxymethylbenzoin sulfonate and the like can be exemplified as the initiator of the latent sulfuric acid series, without being limited thereto.

In one example, the encapsulating composition of the present application may comprise a photoinitiator comprising a sulfonium salt as the photoinitiator in the above-mentioned specific composition, so as to be suitable for a use sealing an organic electronic element by an inkjet method. Even if the encapsulating composition according to the above composition is directly sealed on the organic electronic element, it can prevent chemical damage from being applied to the element due to a small amount of generated outgas. Furthermore, the photoinitiator comprising a sulfonium salt may also have excellent solubility, thereby being suitably applied to an inkjet process.

In an embodiment of the present application, the photoinitiator may be present in an amount of 1 to 15 parts by weight, 2 to 13 parts by weight or 3 to 11 parts by weight, relative to 100 parts by weight of the entire curable compound in the composition. By controlling the photoinitiator content range, due to the nature of the encapsulating composition of the present application that is directly applied on an organic electronic element, the present application can minimize physical and chemical damage to the element.

In an embodiment of the present application, the encapsulating composition may further comprise a photosensitizer in order to complement the curing property at a long wavelength activation energy beam of 300 nm or more. The photosensitizer may be a compound that absorbs a wavelength in a range of 200 nm to 400 nm.

The photosensitizer may be one or more selected from the group consisting of an anthracene-based compound such as anthracene, 9,10-dibutoxyanthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene and 2-ethyl-9,10-dimethoxyanthracene; a benzophenone-based compound such as benzophenone, 4,4-bis(dimethylamino)benzophenone, 4,4-bis(diethylamino)benzophenone, 2,4,6-trimethylaminobenzophenone, methyl-o-benzolybenzoate, 3,3-dimethyl-4-methoxybenzophenone and 3,3,4,4-tetra(t-butylperoxycarbonyl)benzophenone; a ketone-based compound such as acetophenone, dimethoxyacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one and propanone; perylene; a fluorene-based compound such as 9-fluorenone, 2-chloro-9-proprenone and 2-methyl-9-fluorenone; a thioxanthone-based compound such as thioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 1-chloro-4-propyloxythioxanthone, isopropylthioxanthone (ITX) and diisopropylthioxanthone; a xanthone-based compound such as xanthone and 2-methylxanthone; an anthraquinone-based compound such as anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, t-butylanthraquinone and 2,6-dichloro-9,10-anthraquinone; an acridine-based compound such as 9-phenylacridine, 1,7-bis(9-acridinyl)heptane, 1,5-bis(9-acridinylpentane) and 1,3-bis(9-acridinyl)propane; a dicarbonyl compound such as benzyl, 1,7,7-trimethyl-bicyclo[2,2,1]heptane-2,3-dione and 9,10-phenanthrenequinone; a phosphine oxide-based compound such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide; a benzoate-based compound such as methyl-4-(dimethylamino) benzoate, ethyl-4-(dimethylamino) benzoate and 2-n-butoxyethyl-4-(dimethylamino) benzoate; an amino synergist such as 2,5-bis(4-diethylaminobenzal)cyclopentanone, 2,6-bis(4-diethylaminobenzal)cyclohexanone and 2,6-bis(4-diethylaminobenzal)-4-methyl-cyclopentanone; a coumarin-based compound such as 3,3-carbonylvinyl-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(diethylamino)coumarin, 3-benzoyl-7-(diethylamino)coumarin, 3-benzoyl-7-methoxy-coumarin and 10,10-carbonylbis[1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H—Cl]-[6,7,8-ij]-quinolizin-11-one; a chalcone compound such as 4-diethylaminochalcone and 4-azidobenzalacetophenone; 2-benzoylmethylene; and 3-methyl-b-naphthothiazoline.

The photosensitizer may be included in a range of 28 to 40 parts by weight, 31 to 38 parts by weight or 32 to 36 parts by weight, relative to 100 parts by weight of the photoinitiator. By controlling the content of the photosensitizer, the present invention can realize a synergistic action of curing sensitivity at a desired wavelength, and also prevent the photosensitizer from lowering the adhesive force by not dissolving in the inkjet coating.

The encapsulating composition of the present application may further comprise a coupling agent. The present application can improve adhesiveness of a cured product of the encapsulating composition to an adherend or moisture transmission resistance of the cured product. The coupling agent may include, for example, a titanium-based coupling agent, an aluminum-based coupling agent, or a silane coupling agent.

In an embodiment of the present application, the silane coupling agent may include, specifically, an epoxy-based silane coupling agent such as 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyl (dimethoxy)methylsilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; a mercapto-based silane coupling agent such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane and 11-mercaptoundecyltrimethoxysilane; an amino-based silane coupling agent such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, N-phenyl-3-aminopropyltrimethoxysilane, N-methylaminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and N-(2-aminoethyl)-3-aminopropyldimethoxymethylsilane; a ureide-based silane coupling agent such as 3-ureidepropyltriethoxysilane; a vinyl-based silane coupling agent such as vinyltrimethoxysilane, vinyltriethoxysilane and vinylmethyldiethoxysilane; a styryl-based silane coupling agent such as p-styryltrimethoxysilane; an acrylate-based silane coupling agent such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane; an isocyanate-based silane coupling agent such as 3-isocyanatopropyltrimethoxysilane; a sulfide-based silane coupling agent such as bis(triethoxysilylpropyl)disulfide and bis(triethoxysilylpropyl)tetrasulfide; phenyltrimethoxysilane, methacryloxypropyltrimethoxysilane, imidazolesilane, triazinesilane, and the like.

In the present application, the coupling agent may be included in an amount of 0.1 to 10 parts by weight or 0.5 to 5 parts by weight, relative to 100 parts by weight of the entire curable compound. Within the above range, the present application can realize an effect of improving the adhesiveness by the addition of the coupling agent.

The encapsulating composition of the present application may comprise, if necessary, a moisture adsorbent. The term “moisture adsorbent” can be used to generically mean a component capable of adsorbing or removing moisture or humidity introduced from the outside through a physical or chemical reaction or the like. That is, it means a moisture-reactive adsorbent or a physical adsorbent, and a mixture thereof is also usable.

A specific kind of the usable moisture adsorbent in the present application is not particularly limited, which may include, for example, one or a mixture of two or more of a metal oxide, a metal salt or phosphorus pentoxide (P₂O₅), and the like, in the case of a moisture-reactive adsorbent, and may include zeolite, zirconia or montmorillonite, and the like, in the case of the physical adsorbent.

The encapsulating composition of the present application may comprise the moisture adsorbent in an amount of 5 parts by weight to 100 parts by weight, 5 to 80 parts by weight, 5 parts by weight to 70 parts by weight or 10 to 30 parts by weight, relative to 100 parts by weight of the entire curable compound. As the encapsulating composition of the present application preferably controls the content of the moisture adsorbent to 5 parts by weight or more, the present application can make the encapsulating composition or the cured product thereof exhibit excellent moisture and humidity barrier properties. In addition, by controlling the content of the moisture adsorbent to 100 parts by weight or less, the present application can provide a thin film sealing structure.

In one example, the encapsulating composition may further comprise an inorganic filler, if necessary. The specific type of the usable filler in the present application is not particularly limited, and for example, one or a mixture of two or more of clay, talc, alumina, calcium carbonate, silica, and the like may be used.

The encapsulating composition of the present application may comprise 0 to 50 parts by weight, 1 to 40 parts by weight, 1 to 20 parts by weight, or 1 to 10 parts by weight of inorganic filler, relative to 100 parts by weight of the entire curable compound. The present application can provide a sealing structure having excellent moisture or humidity barrier properties and mechanical properties by controlling the inorganic filler, preferably, to 1 part by weight or more. Furthermore, by controlling the content of the inorganic filler to 50 parts by weight or less, the present invention can provide a cured product exhibiting excellent moisture barrier properties even when formed into a thin film.

In addition to the above-mentioned constitutions, the encapsulating composition according to the present application may comprise various additives in the range without affecting the above-described effects of invention. For example, the encapsulating composition may comprise a defoamer, a tackifier, an ultraviolet stabilizer or an antioxidant and the like in an appropriate range of content depending on the desired physical properties.

In one example, the encapsulating composition may be in a liquid phase at room temperature, for example, at about 25° C. In an embodiment of the present application, the encapsulating composition may be in a solventless type liquid phase. The encapsulating composition may be applied to sealing an organic electronic element, and specifically, may be applied to sealing the entire surface of the organic electronic element. As the encapsulating composition has a liquid form at room temperature, the present application can seal the organic electronic element by a method of applying the composition to the side of the element.

Also, the encapsulating composition of the present application may be an ink composition. The encapsulating composition of the present application may be an ink composition capable of an inkjet process. The encapsulating composition of the present application may have a specific composition and physical properties so that ink-jetting can be performed.

In one example, the encapsulating composition of the present application may have an amount of volatile organic compounds measured after curing of less than 50 ppm. The volatile organic compounds may be measured after curing the encapsulating composition and then holding a sample of the cured product at 110° C. for 30 minutes using Purge & Trap-gas chromatography/mass spectrometry. The measurement may be performed using a Purge & Trap sampler (JAI JTD-505 III)-GC/MS (Agilent 7890b/5977a) instrument.

Furthermore, in an embodiment of the present application, the encapsulating composition may have a viscosity in a range of 50 cPs or less, 1 to 46 cPs, or 5 to 44 cPs, as measured by Brookfield's DV-3 at a temperature of 25° C., a torque of 90% and a shear rate of 100 rpm. By controlling the viscosity of the composition within the above range, the present application can increase coating properties at the time of being applied to an organic electronic element to provide a sealing material of a thin film.

Also, in an embodiment of the present application, the encapsulating composition may have a light transmittance of 90% or more, 92% or more, or 95% or more in the visible light region after curing. Within the above range, the present application provides an organic electronic device having high-resolution, low power consumption and long-life by applying the encapsulating composition to a top emission type organic electronic device.

Furthermore, the encapsulating composition of the present application may have a haze of 3% or less, 2% or less or 1% or less according to JIS K7105 standard test after curing, and the lower limit is not particularly limited, but may be 0%. Within the haze range, the encapsulating composition may have excellent optical properties after curing.

In this specification, the above-mentioned light transmittance or haze may be measured in a state where the encapsulating composition is cured to an organic layer, and may be optical characteristics measured when the thickness of the organic layer is any one thickness of 2 μm to 50 μm. In an embodiment of the present application, in order to realize the optical characteristics, the above-mentioned moisture adsorbent or inorganic filler may not be included.

The present application also relates to an organic electronic device. As shown in FIG. 1, an exemplary organic electronic device (3) may comprise a substrate (31); an organic electronic element (32) formed on the substrate (31); and an organic layer (33) sealing the entire surface of the organic electronic element (32) and comprising the above-described encapsulating composition.

In an embodiment of the present application, the organic electronic element may comprise a first electrode layer, an organic layer formed on the first electrode layer and containing at least a light emitting layer, and a second electrode layer formed on the organic layer. The first electrode layer may be a transparent electrode layer or a reflective electrode layer, and the second electrode layer may also be a transparent electrode layer or a reflective electrode layer. More specifically, the organic electronic element may comprise a reflective electrode layer formed on a substrate, an organic layer formed on the reflective electrode layer and containing at least a light emitting layer, and a transparent electrode layer formed on the organic layer.

In the present application, the organic electronic element (23) may be an organic light emitting diode.

In one example, the organic electronic device according to the present application may be a top emission type, but is not limited thereto, and may be applied to a bottom emission type.

The organic electronic device may further comprise a protective layer (35) for protecting the electrodes and the light emitting layer of the element. The protective layer may be an inorganic protective layer (35). The protective layer may be a protective layer by chemical vapor deposition (CVD), where as the material, a known inorganic material may be used and for example, silicon nitride (SiNx) may be used. In one example, silicon nitride (SiNx) used as the protective layer can be deposited to a thickness of 0.01 μm to 5 μm.

In an embodiment of the present application, the organic electronic device (3) may further comprise an inorganic layer (34) formed on the organic layer (33). The material of the inorganic layer (34) is not limited, which may be the same as or different from the above-described protective layer. In one example, the inorganic layer may be one or more metal oxides or nitrides selected from the group consisting of Al, Zr, Ti, Hf, Ta, In, Sn, Zn and Si. The inorganic layer may have a thickness of 5 to 100 nm, 10 nm to 90 nm, or 10 to 80 nm. In one example, the inorganic layer of the present application may be an inorganic material without any dopant, or may be an inorganic material containing a dopant. The dopant which may be doped may be one or more elements selected from the group consisting of Ga, Si, Ge, Al, Sn, Ge, B, In, Tl, Sc, V, Cr, Mn, Fe, Co and Ni, or an oxide of the element, but is not limited thereto.

In one example, the organic layer may have a thickness in a range of 2 μm to 20 μm, 2.5 μm to 15 μm, and 2.8 μm to 9 μm. The present application may provide a thin-film organic electronic device by providing a thin organic layer.

The organic electronic device (3) of the present application may comprise a sealing structure comprising the organic layer (33) and the inorganic layer (34), as described above, where the sealing structure may comprise at least one or more organic layers and at least one or more inorganic layers, and the organic layer and the inorganic layer may be repeatedly laminated. For example, the organic electronic device may have a structure of substrate (31)/organic electronic element (32)/protective layer (35)/(organic layer (33)/inorganic layer (34))n, where n may be a number in a range of 1 to 100. FIG. 1 is a cross-sectional view exemplarily showing a case where n is 1.

The organic layer (33) can seal the upper surface of the element (32), and can seal the side surfaces together as well as the upper surface. In one example, the organic electronic device (3) of the present application may further comprise a cover substrate present on the organic layer (33). The material of the substrate and/or the cover substrate is not particularly limited, and a known material in the art may be used. For example, the substrate or the cover substrate may be glass, a metal base material or a polymer film. As the polymer film, for example, a polyethylene terephthalate film, a polytetrafluoroethylene film, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a vinyl chloride copolymer film, a polyurethane film, an ethylene-vinyl acetate film, an ethylene-propylene copolymer film, an ethylene-ethyl acrylate copolymer film, an ethylene-methyl acrylate copolymer film or a polyimide film and the like may be used.

Also, as shown in FIG. 2, the organic electronic device (3) may further comprise a encapsulation film (37) existing between the cover substrate (38) and the substrate (31) on which the organic electronic element (32) is formed. The encapsulation film (37) may be applied as a use for attaching the substrate (31) on which the organic electronic element (32) is formed and the cover substrate (38), which may be, for example, a pressure-sensitive adhesive film or an adhesive film, but is not limited thereto. The encapsulation film (37) may seal the entire surface of the sealing structure (36) of the above-described organic layer and inorganic layer, laminated on the organic electronic element (32).

The present application also relates to a method for manufacturing an organic electronic device.

In one example, the manufacturing method may comprise a step of forming an organic layer (33) on a substrate (31) in which an organic electronic element (32) is formed on its upper part, so that the above-described encapsulating composition seals the entire surface of the organic electronic element (32). Here, the organic electronic element (32) may be produced by forming a reflective electrode or a transparent electrode on a substrate (31) such as glass or a polymer film, as a substrate (31), by a method such as vacuum deposition or sputtering, and forming an organic material layer on the reflective electrode. The organic material layer may comprise a hole injecting layer, a hole transporting layer, a light emitting layer, an electron injecting layer, and/or an electron transporting layer. Subsequently, a second electrode is further formed on the organic material layer. The second electrode may be a transparent electrode or a reflective electrode.

The manufacturing method of the present application may further comprise a step of forming a protective layer (35) on the first electrode, the organic material layer and the second electrode, formed on the substrate (32). Then, the above-described organic layer (33) is applied to cover the entire surface of the organic electronic element (32) on the substrate (31). Here, the step of forming the organic layer (33) is not particularly limited and the above-described encapsulating composition may be applied to the entire surface of the substrate (31) using a process such as inkjet printing, gravure coating, spin coating, screen printing or reverse offset coating.

The manufacturing method may further comprise a step of irradiating the organic layer with light. In the present invention, a curing process may also be performed on an organic layer sealing an organic electronic device, and such a curing process may be performed, for example, in a heating chamber or a UV chamber, and preferably, may be performed in a UV chamber.

In one example, after the above-described encapsulating composition is applied to form a entire surface organic layer, the composition can be irradiated with light to induce cross-linking. The irradiation of light may comprise irradiating with light having a wavelength range of 250 nm to 450 nm or 300 nm to 450 nm region bands at a light quantity of 0.3 to 6 J/cm² or a light quantity of 0.5 to 5 J/cm².

In addition, the manufacturing method of the present application may further comprise a step of forming an inorganic layer (34) on the organic layer (33). As the step of forming an inorganic layer, a known method in the art may be used, which may be the same as or different from the above-described method of forming a protective layer.

Advantageous Effects

The present application provides an encapsulating composition which can effectively block moisture or oxygen introduced into an organic electronic device from the outside to secure the lifetime of the organic electronic device, is possible to realize a top emission type organic electronic device, is applicable to an inkjet method and can provide a thin display, and an organic electronic device comprising the same.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1 and 2 are cross-sectional views showing an organic electronic device according to one example of the present invention.

EXPLANATION OF REFERENCE NUMERALS

-   -   3: organic electronic device     -   31: substrate     -   32: organic electronic element     -   33: organic layer     -   34: inorganic layer     -   35: protective layer     -   36: sealing structure     -   37: encapsulation film     -   38: cover substrate

BEST MODE

Hereinafter, the present invention will be described in more detail through Examples according to the present invention and Comparative Examples not complying with the present invention, but the scope of the present invention is not limited by the following examples.

Example 1

An alicyclic epoxy compound (Celloxide 2021P, Daicel Corp.), an aliphatic epoxy compound of 1,4-butanediol diglycidyl ether (DE200, HAJIN CHEM TECH), a monofunctional curable compound of o-cresyl glycidyl ether (LS692 from HAJIN CHEM TECH) and an oxetane group-containing curable compound (OXT-212 from TOAGOSEI), as curable compounds, were introduced into a mixing vessel in a weight ratio of 16:18:18:39.95 (Celloxide2021P: DE200: LS692: OXT-212) at room temperature. 3.3 parts by weight of a photopolymerization initiator (UV693 from TETRA CHEM), 1.1 parts by weight of a fluorine-based surfactant (F447 from DIC), 3.3 parts by weight of a coupling agent (KBE-402, SHIN-ETSU) and 0.05 parts by weight of a heat stabilizer, 2,6-di-tert-butyl-p-cresol (BHT from SIGMA aldrich), relative to 100 pats by weight of the entire curable compound, were further introduced to the mixing vessel. Also, 33.3 parts by weight of a photosensitizer, 9,10-2-ethyl-9,10-dimethoxyanthracene (SIGMA aldrich), relative to 100 parts by weight of the photopolymerization initiator was further introduced to the mixing vessel.

In the mixing vessel, a uniform encapsulating composition ink was prepared using a planetary mixer (Kurabo, KK-250s).

Example 2

An encapsulating composition was prepared in the same manner as in Example 1, except that FC-4430 (3M Co.), a fluorine-based surfactant, was used instead of F447 as a surfactant.

Comparative Example 1

An encapsulating composition was prepared in the same manner as in Example 1, except that D8526 (Dow Corning), a silicone-based surfactant, was used instead of F447 as a surfactant.

Comparative Example 2

An encapsulating composition was prepared in the same manner as in Example 1, except that T2500 (TEGO), a silicone-based surfactant, was used instead of F447 as a surfactant.

Comparative Example 3

An encapsulating composition was prepared in the same manner as in Example 1, except that B348 (BYK), a silicone-based surfactant, was used instead of F447 as a surfactant.

Comparative Example 4

An encapsulating composition was prepared in the same manner as in Example 1, except that Q2-5211 (Dow Corning), a silicone-based surfactant, was used instead of F447 as a surfactant.

Comparative Example 5

An encapsulating composition was prepared in the same manner as in Example 1, except that an alicyclic epoxy compound (Celloxide 2021P, Daicel Corp.), an aliphatic epoxy compound of 1,4-butanediol diglycidyl ether (DE200, HAJIN CHEM TECH), a monofunctional curable compound of o-cresyl glycidyl ether (HAJIN CHEM TECH) and an oxetane group-containing curable compound (OXT-121 from TOAGOSEI), as curable compounds, were introduced into a mixing vessel in a weight ratio of 15:4:24:46.95 (Celloxide2021P: DE200:o-cresyl glycidyl ether:OXT-121).

Comparative Example 6

An alicyclic epoxy compound (Celloxide 8010 from Daicel Corp.), an aliphatic epoxy compound of 1,4-butanediol diglycidyl ether (DE200, HAJIN CHEM TECH), a monofunctional curable compound of 2-ethylhexyl glycidyl ether (SIGMA aldrich) and an oxetane group-containing curable compound (OXT-212 from TOAGOSEI), as curable compounds, were introduced into a mixing vessel in a weight ratio of 17:10:7:58.45 (Celloxide2021P:DE200:2-ethylhexyl glycidyl ether:OXT-212) at room temperature. 3.2 parts by weight of a photopolymerization initiator (1290), 1.1 parts by weight of a fluorine-based surfactant (F552 from DIC), 3.2 parts by weight of a coupling agent (KBM-303, SHIN-ETSU) and 0.05 parts by weight of heat stabilizer, 2,6-di-tert-butyl-alpha-methoxy-para-cresol (SIGMA aldrich), relative to 100 parts by weight of the entire curable compound, were further introduced to the mixing vessel. Also, 16.7 parts by weight of a photosensitizer, 9,10-dibutoxyanthracene (DBA from SIGMA aldrich), relative to 100 parts by weight of the photopolymerization initiator, was further introduced to the mixing vessel.

In the mixing vessel, a uniform encapsulating composition ink was prepared using a planetary mixer (Kurabo, KK-250s).

Comparative Example 7

An alicyclic epoxy compound (Celloxide 2021P from Daicel Corp.), an aliphatic epoxy compound of 1,4-butanediol diglycidyl ether (DE200, HAJIN CHEM TECH), a monofunctional curable compound of o-cresyl glycidyl ether (HAXIN CHEM TECH) and an oxetane group-containing curable compound (OXT-212 from TOAGOSEI), as curable compounds, were introduced into a mixing vessel in a weight ratio of 22:25:35:9.95 (Celloxide2021P:DE200:o-cresyl glycidyl ether:OXT-212) at room temperature. 3.3 parts by weight of a photopolymerization initiator (Irgacure PAG 290 from BASF, hereinafter, 1290), 1.1 parts by weight of a fluorine-based surfactant (F552 from DIC), 3.3 parts by weight of a coupling agent (KBM-303, SHIN-ETSU) and 0.05 parts by weight of a heat stabilizer, 2,6-di-tert-butyl-alpha-methoxy-para-cresol (SIGMA aldrich), relative to 100 parts by weight of the entire curable compound, were introduced to the mixing vessel. Also, 33.3 parts by weight of a photosensitizer, 9,10-dibutoxyanthracene (DBA from SIGMA aldrich), relative to 100 parts by weight of the photopolymerization initiator, was further introduced to the mixing vessel.

In the mixing vessel, a uniform encapsulating composition ink was prepared using a planetary mixer (Kurabo, KK-250s).

Physical properties in Examples and Comparative Examples were evaluated in the following manner.

1. Surface Energy Measurement

Each surface energy of the encapsulating compositions prepared in Examples and Comparative Examples was measured using a drop shape analyzer (DSA100 product from KRUSS). After the encapsulating composition is applied on a SiNx substrate to a thickness of 50 μm and a coating area of 4 cm² (width: 2 cm, height: 2 cm) to form a sealing layer (spincoater), it is dried at room temperature for about 10 minutes under a nitrogen atmosphere and then UV-cured with an intensity of 1000 mW/cm² through a light quantity of 4000 mJ/cm². The process of dropping the deionized water whose surface tension is known on the layer after curing, and obtaining the contact angle thereof is repeated five times to obtain an average value of the obtained five contact angle values, and identically, the process of dropping the diiodomethane whose surface tension is known thereon and obtaining the contact angle thereof is repeated five times to obtain an average value of the obtained five contact angle values. Then, the surface energy was obtained by substituting the value (Strom value) regarding the solvent surface tension by the Owens-Wendt-Rabel-Kaelble method using the obtained average values of the contact angles for the deionized water and diiodomethane.

2. Surface Roughness Measurement

The encapsulating compositions prepared in Examples and Comparative Examples are each applied on a SiNx substrate to a thickness of about 50 μm and UV-cured at an intensity of 1000 mW/cm² through a light quantity of 4000 mJ/cm² to form a sealing layer. Surface roughness was measured using NX10 from Park Systems.

[Parameter]

Mode: intermittent (Tapping), Samples/line: 256×256, Scan rate: 0.9-1.0 Hz

[Afm Probe]

PPP-CHR (Nanosensor), Material: Al coating on detector side of cantilever, Resonance Frequency: 204-497 kHz, Force Constant: 10-130 N/m

3. Upper Adhesion Evaluation

The encapsulating compositions prepared in Examples and Comparative Examples were each applied on a SiNx substrate to a thickness of about 50 μm and UV-cured at an intensity of 1000 mW/cm² through a light quantity of 4000 mJ/cm² to form a sealing layer. Silicon nitride (SiNx) was deposited on the sealing layer through chemical vapor deposition (CVD) to form an inorganic layer having a thickness of 2 μm.

The laminated structure was held under 85° C. and 85% relative humidity for 740 hours, and then a peeling phenomenon was observed in the laminated structure. It was represented as O in the case where the peeling of the laminated structure occurred, and as X in the case where no peeling occurred.

TABLE 1 Surface Surface energy roughness Upper (mN/m) (nm) adhesion Remarks Example 1 25.4 0.3 ◯ — Example 2 24.7 0.8 ◯ — Comparative Example 1 22.6 6 X — Comparative Example 2 23.9 4 X — Comparative Example 3 31.5 3 X — Comparative Example 4 18.9 0.4 X — Comparative Example 5 32.9 4 X — Comparative Example 6 29.7 7 X — Comparative Example 7 33.3 2 X — 

1. An encapsulating composition comprising: a curable compound having one or more curable functional groups; and a surfactant having a polar functional group, wherein the surfactant is a non-silicone-based surfactant, wherein the encapsulating composition has a surface energy after curing in a form of a sealing layer in a range of 20 mN/m to 30 mN/m and a surface roughness of 3.5 nm or less.
 2. (canceled)
 3. The encapsulating composition according to claim 1, wherein the curable functional group is one or more selected from the group consisting of an oxetane group, a glycidyl group, an isocyanate group, a hydroxyl group, a carboxyl group, an amide group, an epoxide group, a sulfide group, an acetal group and a lactone group.
 4. The encapsulating composition according to claim 1, wherein the curable compound comprises a curable compound having a cyclic structure in its molecular structure and having at least two or more curable functional groups.
 5. The encapsulating composition according to claim 4, wherein the compound having a cyclic structure in its molecular structure has ring constituent atoms in the molecular structure in a range of 3 to
 10. 6. The encapsulating composition according to claim 4, wherein the curable compound further comprises a monofunctional curable compound.
 7. The encapsulating composition according to claim 6, wherein the monofunctional curable compound is comprised in a range of 65 parts by weight to 165 parts by weight relative to 100 parts by weight of the curable compound having a cyclic structure.
 8. The encapsulating composition according to claim 4, wherein the curable compound further comprises a linear or branched aliphatic curable compound.
 9. The encapsulating composition according to claim 8, wherein the aliphatic curable compound has two or more curable functional groups.
 10. The encapsulating composition according to claim 8, wherein the aliphatic curable compound is comprised in a range of 20 parts by weight or more and less than 205 parts by weight relative to 100 parts by weight of the curable compound having a cyclic structure.
 11. The encapsulating composition according to claim 4, wherein the curable compound further comprises a curable compound having an oxetane group.
 12. The encapsulating composition according to claim 11, wherein the curable compound having an oxetane group has two or more oxetane groups.
 13. The encapsulating composition according to claim 11, wherein the curable compound having an oxetane group is comprised in an amount of 50 parts by weight to 150 parts by weight relative to 100 parts by weight of the curable compound having a cyclic structure and the monofunctional curable compound.
 14. (canceled)
 15. (canceled)
 16. The encapsulating composition according to claim 1, wherein the surfactant comprises a fluorine-based compound.
 17. The encapsulating composition according to claim 1, wherein the surfactant is comprised in an amount of 0.01 parts by weight to 10 parts by weight relative to 100 parts by weight of the entire curable compound.
 18. The encapsulating composition according to claim 1, further comprising a photoinitiator.
 19. An organic electronic device comprising a substrate; an organic electronic element formed on the substrate; and an organic layer sealing the entire surface of the organic electronic element and comprising the encapsulating composition according to claim
 1. 20. A method for manufacturing an organic electronic device comprising a step of forming an organic layer on a substrate in which an organic electronic element is formed on its upper part, so that the encapsulating composition of claim 1 seals the entire surface of the organic electronic element.
 21. The method for manufacturing an organic electronic device according to claim 20, wherein the step of forming an organic layer comprises inkjet printing, gravure coating, spin coating, screen printing or reverse offset coating. 